Hey guys,

Well I ventured out to my club today for the first time. I met with a bunch of really nice folks all there to have a good time, help and maybe learn something.

As luck would have it, during my first check-out by an instructor, we started experiencing significant servo gitter. Well after much discussion, elimination and experimentation, we narrowed down the issue to the transmitter itself (the definitive test was when we took out my tx crystal and put it into someone elses tx, yielding a perfectly flyable setup... no jitter!)

So what can go wrong inside there? This is the first time I've had it out; a Futaba 6EXA. I plan on taking it back to my LHS, but to satisfy my own curiousity, I'd like to understand a bit more about what goes on inside, and where potential breakdowns can occur.

Hopefully I can get this tx either replaced at the lhs, or fixed soon. Talk about frustrating!!

Thanks guys

Ooooo..... sorry to hear that. Hopefully, they can get you swapped out for a good one and get you going. Luck!

Seriously, it's rare, but theres LOTS of things that can go wrong(too many for me to type). I'm glad you're taking it back instead of trying to fight with it.

I've never had a transmitter go wrong on me, but unless it is defective to start out with, I would say things that CAN go wrong are dropping it (obviously), gettting it wet (flying in the rain or spilling something in it) or burning up the RF unit by leaving it on with the antenna down. I do that all the time in my shop even though the manufacturer specifically says not to and I haven't had any problems.

More often than not, servo jitter is a problem with the flight pack and usually some type of bad setup such as metal to metal that vibrates when the engine is running.

If you can't specifically pinpoint the problem then I would send the whole thing back and have them take a look at it. If the problem seems to disappear by itself then you can almost count on it returning when your plane is in the air which will most likely have a catastrophic outcome.

I hope you get it squared away. Nothing is worse than a problem that can't be found.

Well I took it back to the LHS and the best they can do is ship it off to Futaba. 2-3 weeks, and with the holidays maybe longer... talk about bad luck.

I was actually hoping they would swap it out for me. I bought it about 6 weeks ago, but this is the first time I had it out to use. I understand why they didn't but still on some level I was hoping they would realize that I'd be grounded until I get the tx back. Tuff break for a new flyer I guess.

Well we'll see what Futaba comes back with. After the detective work at the airfield today, I'm conviced its a defective Tx. Thanks for listening folks. Nice to vent a bit here...

That is a bad break, but most hobby shops would have done the same thing. Use the time to go over your plane and make sure it's flight worthy. You might start on your next project or improve your workshop. Lots to do in this hobby even when you're grounded.

Ive had many Futaba radios, but the problems like you described almost always were associated with the electronics in the airplane. I know one gent that was using JR and had a similar problem. The final problem was that the antenna was not screwed in firmly. Always something simple, but always hard to find or figure out. If you had a flying buddy with the same channel, you could have him check your plane using his radio to eliminate an airplane problem. Or since Futaba receivers are high or low, you could have a friend put in a compatible receiver crystal in your receiver and range check your plane to ensure it is not in the airplane. Remember, a good range check is done with the engine running and shut off, to make sure engine vibrations are not causing loose metal parts to chatter and generate RFI. Hope this helps. You already got some good leads from our friends above. Good luck and happy landings.

Basically, thats what we did. We took the crystal out of my Tx, and dropped it into a different Tx (both Low band, one channel apart). We then range checked it and had absolutly zero problems. This pretty well convinced all the experienced folks watching that the issue was in the Tx, not the Rx or servos themselves.

So, three weeks from now (hopefully) we'll have our answer. I'll be sure to post an update!

many things can go wrong but its rare today. had 3 futabas fail on me .one with rf output (crash)intermitent. two suffered failure of channel to elevator servo in the DOWN position only. still gave up.verified by swapping moduals on identical tx's. servo was not the problem. loose anttena can still cause crash. also seen a RX anttena loose from the circuit board or hanging by a thread. i have also seen RX's work perfectly untill the engine was started then quit.hairline fracture of board.